What two reasons can be attributed to the rapid spread of the viruses?

What are the most explosive events that occur on the sun? umbras solar flares solar winds prominences

The finches on the galapagos island were similar in form except for variations of their beaks. darwin observed that these variations were useful for: attracting a mate defending territory building nests gathering food

Which is a function performed by stem cells in the skin a. replacing lost skin cells b. making cells for the intestines c. growing new organs d. differentiating into brain cells plz apex